This invention relates to intraluminal catheters and particularly to electrophysiology (EP) catheters having distal tips which are shapable after insertion to a patient's body lumen.
EP catheters generally have elongated catheter shafts with one or more electrodes on their distal ends to detect electrical activity or to emit high frequency, e.g. RF, electrical energy, to ablate tissue within a patient's body. Such catheters have been used to detect electrical activity within a patient's heart to determine the location of tissue causing arrhythmia, and to ablate tissue causing arrhythmia once the location of the tissue causing the arrhythmia has been determined.
The distal extremities of EP catheters frequently need to be deflected or shaped within the patient in order to guide the distal extremity into a desireable body lumen or chamber. For example, it is very difficult to advance an EP catheter into a patient's coronary sinus from the inferior vena cava. In other instances it is desireable to shape the distal extremity of an EP catheter to more closely conform the shape of the distal extremity to the patient's endocardium when detecting electrical activity. It is also desireable to shape the distal extremity of an ablation type catheter to orient the distal tip thereof with respect to tissue, such as a patient's endocardium, to facilitate proper delivery of RF energy, laser energy and the like. U.S. Pat. No. 5,190,050 (Nitzche) is an example of an EP type catheter with a deflectable distal tip.
The prior catheters which have a deflection mechanism are usually limited to uniplanar deflection which requires the catheter shaft to be rotated from its proximal end located outside of the patient in order to place the deflected tip into a desired plane, e.g. to seat the distal tip of the catheter into a desired branch of a blood vessel. Unfortunately, the torque applied at the proximal end does not always result in the same rotation at the distal end. Frequently, the catheter shaft will store up the torque and then suddenly release the stored up torque, causing the distal end to suddenly rotate, i.e. whip. Providing a catheter shaft with sufficient strength to transmit to the distal end torque which is applied to the proximal end can increase the stiffness of the shaft to the extent that advancement through tortuous anatomy is difficult.
What has been needed and has heretofore been unavailable is an EP type catheter which has a distal tip with the capability for universal deflection from its longitudinal axis without requiring the entire catheter to be rotated from its proximal end. The present invention satisfies these and other needs.